Commit 46224853 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'net-control-the-length-of-the-altname-list' 

Jakub Kicinski says:

====================
net: control the length of the altname list

Count the memory used for altnames and don't let user
overflow the property nlattr. This was reported by George:
https://lore.kernel.org/all/3e564baf-a1dd-122e-2882-ff143f7eb578@gmail.com/
====================

Link: https://lore.kernel.org/r/20220309182914.423834-1-kuba@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 1926407a 155fb43b

net/core/rtnetlink.c

+12 −1
Original line number Diff line number Diff line
@@ -3652,13 +3652,24 @@ static int rtnl_alt_ifname(int cmd, struct net_device *dev, struct nlattr *attr, 
			   bool *changed, struct netlink_ext_ack *extack)

{

	char *alt_ifname;

	size_t size;

	int err;



	err = nla_validate(attr, attr->nla_len, IFLA_MAX, ifla_policy, extack);

	if (err)

		return err;



	alt_ifname = nla_strdup(attr, GFP_KERNEL);

	if (cmd == RTM_NEWLINKPROP) {

		size = rtnl_prop_list_size(dev);

		size += nla_total_size(ALTIFNAMSIZ);

		if (size >= U16_MAX) {

			NL_SET_ERR_MSG(extack,

				       "effective property list too long");

			return -EINVAL;

		}

	}



	alt_ifname = nla_strdup(attr, GFP_KERNEL_ACCOUNT);

	if (!alt_ifname)

		return -ENOMEM;